1. Field of the Invention
This invention relates to gaseous and liquid fuel engines and more particularly to a device for curtailing tampering with the fuel adjustments of such engines.
2. Description of the Related Art
Once the carburetor adjustments or other adjustment screws of an engine using gasoline or natural gas have been properly set for optimum performance commensurate with minimum pollutant emission, it is highly undesirable if these settings are tampered with. Such changing of the settings could both increase the pollutant emissions to an unacceptable level and decrease the efficiency of the operation of the engine.
In an effort to prevent such tampering, various devices have been developed in the prior art. Such devices include a shield which is press fitted in position a housing retaining the adjustment screw as described in U.S. Pat. No. 4,718,828 issued Jan. 12, 1988 to Breeck,et al; a cover for the adjustment screw which is not removable once installed and which includes a slot through which access to the adjustment screw can be obtained only with a special tool as described in U.S. Pat. No. 4,271,095 issued Jun. 2, 1981 to Maeda; a wall in the shape of a hollow tube in which the adjustment member is installed having a plug at one end which can only be removed with a special tool such as described in U.S. Pat. No. 4,308,220 issued Dec. 29, 1981 to Tateno. Other such devices are described in U.S. Pat. No. 4,246,929 issued Jan. 27, 1981 to Wakeman; U.S. Pat. No. 4,272,458 issued Jun. 9, 1981 to Ruth, etal.; U.S. Pat. No. 4,470,769 issued Sep. 11, 1984 to Owens; and U.S. Pat. No. 5,753,148 issued May 19, 1998 to King et al.
The device of the present invention is believed to provide an advantage over these prior art devices by virtue of its simple and economical construction and its capability of providing immediate evidence of actual or attempted tampering with the adjustment.